Individual Functions
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Slave Not Responding
In the following cases, the slave will ignore the write function.
• When a communications error (overrun, framing, parity, or CRC-16) is detected in the command message.
• When the slave address in the command message and the slave address in the Inverter do not match.
• When the gap between two blocks (8 bit) of a message exceeds 24 bits.
• When the command message data length is invalid.
Application Precautions
Self-Diagnosis
The Inverter has a built-in function for self-diagnosing of the serial communication interface circuits. This
function uses the interconnected send/receive terminals and emulates messages.
To perform the self-diagnosis function use the following procedure.
1. Switch ON the Inverter power supply, and set 67 (communications test mode) in parameter H1-05 (Termi-
nal S7 Function Selection).
2. Switch OFF the Inverter power supply.
3. Perform the wiring according to Fig 6.54.
4. Switch ON the terminating resistance. (Turn ON pin 1 on DIP switch 1.)
5. Switch ON the inverter power supply.
Fig 6.54 Communication Terminals Wiring for Self-Diagnosis
If the serial port is working correctly the Digital Operator displays “PASS” on the display.
If an error occurs, a “CE” (MEMOBUS communications error) alarm will be displayed on the Digital Opera-
tor, the fault digital output will be turned ON and the Inverter operation ready signal will be turned OFF.
IMPORTANT
If the slave address specified in the command message is 0, all slaves execute the write function,
but do not return response messages to the master.
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